Behind closed doors
by Attack on MLG
Summary: Detective!Au. The murder of an elderly couple is left in the hands of DCI Smith as he fights to find the printless killer. With problems of his own, Kai realises that he isn't so perfect after all, especially with his sister's new boyfriend coming onto the scene. Only with help from Cole, his closest friend, will the two dive deep into the mind of the only witness; a ten year old.
1. Lucky you

It was another day at work, I guess. The sun was shining brightly through the windows into the main office, the faint sound of birds and dogs letting me relax I bit. Obviously I was pissed off; I always was when Nya did stuff without my permission. Finally she had 'found the one', the man of her dreams, if you will, after being in the same engineering class and tech class.

His name was, Jay, apparently. Jay Walker, to be precise. How convenient that a random boy off her campus, who she was dating, is called that. Of course, I couldn't judge a book by it's cover – I knew better than that – so all I had to do is get along with him. I sighed, regretting flipping out at her this morning and most likely upsetting her very much. I was just stressed, that's all.

"Okay… hmm… so we've got this murder case involving the death of an elderly couple-"

"I'll take it!" I shot my hand up, my voice hitching slightly. Across the room Cole snickered into his coffee cup, leaning over his desk even more. I glanced at him out the corner of my eye and growled teasingly; he was always amused by my enthusiasm. He was clad in his usual snug, brown sweater, which, might I add, contrasted perfectly with the bright shimmer of yellow in his emerald eyes. His cheeks were warmly flushed from his hot morning coffee, his eyes closing slowly as he took another sip.

"Smith, this is a rather sinister case. If I were you I would give this one to one of the higher ups – they have more experience than you." Typical. Ronin chuckled softly, probably finding himself funny or some shit like that.

I glared at him. "C'mon, man. This case seems pretty damn important if you ask me, so I suggest you let me lead it and prove just how good I am. You can't judge someone's skill set just because they aren't as ancient as you." My lips formed into a firm line as I got a few concerned looks from the office team, nodding over at the ginger in self conformation. "You're, like, forty-five."

"And you're, like, being childish." Ronin grumbled to himself as he positioned himself back at the center of the room, his eyes narrowing as he sighed regrettably. "Ugh… fine. Fine." He turned to meet my snarky gaze. "But not on your own. So, um, who's up for it, then?"

"I'll do it." Cole muttered, not looking up from his work log. He licked his lips and looked up at the elder male, before cocking his head to the side like a confused puppy. "Is that okay with you, Sir?"

Ronin nodded firmly; he definitely trusted Cole, more than me. I didn't mind, though. It's fun working with, Cole, anyways– we get up to all sorts of things. "Then it's settled. Bucket… Smithy… there's _a little catch, by the way."_

 _Oh great._

"The only witness is the son, Lloyd. He's ten."

"Can we bring him in for questioning? We should get that done soon enough." I asked and began writing notes in my work log as well, watching Cole do the same.

"We've got forensics on the site as we speak, and the kid is with his Uncle."

"Okay, we need to get both of them in, then." Cole spoke up, now in full concentration mode. "And I'm all up for checking CCTV as well…"

"Yep, definitely. Good work, lads, keep this up and the case'll be over in no time. Oh, and Smith?" My superior stared over at me rather intimidatingly. I raised an eyebrow expectantly. "Don't fuck this up."


	2. Lloyd's bedroom

Cole gagged nervously into his fist, averting his eyes away from the bloody scene before him. The corpses, thank God, had been removed, but everything else was still under harsh analysis. The once clean, white carpet was stained now in crimson and purple, those same colours marking nearby furniture and walls in splatters as well.

"You okay?" Kai cautiously flickered his stare over his friend, clearly concerned.

Cole nodded quickly as he stumbled a bit. "Y-Yeah, just a bit nauseous, that's all. I'll be fine, though."

"You sure? Cole, you don't have to be here if you can't deal with it."

"I can!" He suddenly exclaimed, making Kai flinch. Shaking his head, he sighed, running a hand through his hair. "I can… Sorry. I'm just a bit out of it, that's all. I haven't dealt with cases like this in a while." The brunet hummed approvingly, despite still being worried.

"Good to hear." Kai licked his lips and carefully shuffled around the people inspecting the floors, making his way smoothly over to the staircase at the side of the room. There was a small, but noticeable dent into the wooden bannester, along with the same vital red fluid smeared over it rather aggressively. _Someone must've hit their head real hard on that thing…_ He grimaced at the thought, leading his friend further up the short flight.

Taking the first right, they found themselves in, presumably, Lloyd's bedroom. Considering it was most likely only the ground floor of the house that had became victim to the disturbance, the upstairs was left free of forensic work for the time being. The room was relatively normal -cliché, almost- with sports posters and equipment decorating the dark green walls. Exhaling, Kai crouched down to search under the bed, digging in deeper at the sight of numerous boxes. Cole leant himself comfortably against the wall, peering down silently with a cold stare. Awkwardly Kai removed himself from under the bed, brushing himself down as he pulled out one of the larger boxes. He chuckled lightly and met the raven's gaze, smirking playfully at the dramatic height difference from the floor.

"Woah. No wonder you get neck pains." He laughed and patted the space at the younger boy's feet. Cole folded his arms over his chest coldly and rolled his eyes, unamused.

"I'm up to your jaw. And the pains are from doing a shit ton more work than you do."

"Touché." Kai watched his friend sit down opposite him, crossing his legs neatly.

Standard Cole.

The brunet bit his lip as he dramatically pulled back the latex glove from around his wrist, letting go with an impressive smack as he raised his eyebrows at the clearly more focused DCI. Quickly Kai removed the dusty lid and placed it beside the box, gasping at the contents. "Huh." The underwhelming stash of revision books met their gaze, the hopeful glint instantly extinguished. Kai furrowed his brow as Cole suddenly began emptying the large box, book after book forming small piles next to the lid.

"Kid's… they usually hide random crap under all their school junk."

"Lloyd was homeschooled, though."

"It doesn't matter." Cole interjected, carefully taking out a small shoe box and sliding the now empty box to one side, before setting the new box down in the middle of them. "As long as they have enough 'good student's equipment to cover something, they can hide whatever they need to."

Kai nodded, feeling slightly enlightened. "You never fail to amaze me, Cole. You know that, right?"

"Evidently." He swallowed, not liking the compliment very much.

"I reckon we should let forensics do their job, instead of us potentially contaminating vital evidence." The elder mused, beginning to refill the box. He laughed softly as Cole watched him intently. "I don't understand why you haven't hooked up with a girl yet."

"What are you suggesting." Cole muttered shallowly, glaring over at his friend.

Kai pushed the box back under the bed. "Like, first off, every chick likes a guy in uniform; it's fact." Cole stood up and tugged awkwardly at his tie, grumbling in irritation.

"I'm pretty sure this doesn't count as uniform. And anyways, why are we even discussing my love life? I've got to get back early to see my dad, after all."

Kai stretched as he rose to his feet and nodded cheerfully. "Hm, yeah, I totally get ya. I'll do some extra work tonight then, just to get some off your back."

The raven pursed his lips. "It's fine. I'll be able to pull an all-nighter at some point if I can't catch up." He glanced down as Kai rested a hand on his shoulder, squeezing it assuringly.

The brunet smiled at him, before they walked back down to the ground floor.


	3. Opposite opinions

"Uhhh, d'you want tea or coffee?" Kai asked as he began pulling out two mugs from the cabinet and boiling the kettle.

Cole laughed as he leant against the island. "What d'you think?"

"Coffee it is, then."

It wasn't long before the duo were sipping carefully at the hot drinks, relaxed and peaceful.

It was nice.

The silence wasn't awkward - oh no, not at all. They made sure to savour these rare times in which they were able to simply enjoy each others company.

Shortly after, however, the universe had decided against them.

Kai was first to lower his mug onto the counter he was leaning against, slowly placing it next to the kettle without breaking his sharped gaze from the kitchen's entrance. Cole rolled his eyes at his work partner's sudden change of posture as he, too, put down his mug on the small dining table in the centre of the room and turned to face the entrance also. As expected soon after, a familiar voice called out as the sound of a door unlocking, shoes scuffing on a door mat, and a door re-locking sounded. "I'm home!"

"Same here!" Kai shouted back, inhaling a frustrated breath. "Thanks for getting home early! Really appreciate it!"

Nya greeted him with a cheeky smirk as she sauntered into the kitchen. "Aww, really?"

"No."

"Thought so." She muttered, taking a seat at the table and pulling out her phone. "How're you doing, Cole? You good?"

"Yeah, I'm alright, thanks. You?"

"Not too shabby. All's good on Planet-A-La-Nya." The corners of her lips quirked upwards into a small smile as she didn't take her eyes off her phone, leaning back slightly to shield the screen. "How's the Garmadon case going?"

Kai sipped his drink slowly, licking his lips as he lowered the mug to speak. "I told you."

"That was yesterday." She muttered. "I get that it's confidential and all, but you must be able to let me know a smidge of info."

"I said no, _Nya_. Now drop it."

The ravenette glanced up at her sibling with a dirty glare, before snapping her head to face the other male. "C'mon, Cole. Gimme some beef."

"No can do." He laughed. "You know the rules."

"Ya, but I don't care about them at the moment. Rules are made to be broken you know?"

Cole snorted. "Says the girl who is usually going on about how spotless her record is. God, Kai," He smirked at the brunet. "she's turning into you."

Kai rolled his eyes. "She's spending too much time with a boy, that's the problem. Josh-"

" _Jay._ "

"-whatever. Jay Walker, _then_ , isn't a great role model."

"Jay Walker, huh? Sound like a pretty cool last name. Nya Walker. Has a nice ring to it-"

"Wha– No it doesn't!" Kai exclaimed, before turning sharply to his sister. "Do not even start considering marriage."

Nya beamed at him smugly. "I'm not gonna marry him, Kai… yet." She laughed to herself, sighing. "We've literally only been on… one, two…" She counted on her fingers. "…three- three dates! Or was it four? I dunno. What I'm saying is that marriage is not a priotipr at the moment."

"Good. I hope you you're both agreeing on that."

"Of course we are. Although, I reckon we will stay together after school… we're dreaming on running our own mechanics in the future!"

"Keep dreamin'." The brunet licked his lips as he placed his empty mug down near the kettle, folding his arms over his chest. "You won't have a future if you stay with him."

"Just because you're single doesn't mean you can bully me. Cole's single, and he doesn't."

"Hey, don't bring me into your sibling issues." Cole raised his hands in mock surrender, looking between the two. "This is you guys' shit."

"Nu-uh." Nya shook her head stubbornly. "Hang on, I'll get a photo up of him. Tell me whatcha think…"

Shortly after, Cole was handed over the phone. This 'Jay Walker' wasn't what he'd expected at all – quite the opposite, actually. Naturally tan skin, though not as tan as Kai, with freckled cheeks and unruly brunet hair. His eyes were a mix of ocean blue and a deep navy, which conisidently matched the blue denim jacket and sneakers he was shown wearing; posed against a graffitied brick wall as he created gang signs with his hands.

"Hm, yeah, I can see where Kai is coming from." He handed Nya back her phone as she gasped. "Buuuuuttttt, if you two get along well, then you should stay with him. He clearly has an 'edgy' side, which I know you have. I don't know, Nya, I can't really give you relationship advise."

"You had girlfriends during college right? You said your dad was strict as well, much like Mr Bossy over here."

"Hey-"

"None of the relationships really worked out. They lasted around a couple weeks, but they just didn't work for me." He pursed his lips. "My dad wasn't a great help either. He always went on about how I should get a girlfriend and stuff, when all I really wanted was…" He glanced at Kai. "…to study."

"What he's saying is put work before Jay."

"No I'm not." Cole nodded at the raveneette. "Mental health is better than work. Whatever makes you happy, put it first. And if Jay makes you happy… then by all means, tell Kai to fuck off, and let you spend time with your boyfriend."

Kai facepalmed. " _Jesus Christ._ "

"Finally, someone who actually speaks some sense!" Nya grinned as she stood up, punching Cole playfully in the arm. "Cheers, Cole."

"No problem."

And with that she strolled out the kitchen, leaving Kai to stare disapprovingly at the younger. "You're an idiot."

"Yep. She's your sister, though."

"That doesn't give you the right to encourage her."

"You sound like my dad." He held up his index finger to shush the brunet. "It's not a good thing."

Kai closed his mouth reluctantly. "Dickhead…"

"Hypocrite."


	4. Youth

**Where the fuck have I been? That's a great question. Truth be told, I pretty much forgot this fanfic existed, as I was caught up with my Camp Camp stories :/ (it's a fucking great show, you should check it out)**

 **I'd class this chappie as a filler, or something. It's not very long, but I _just_ scratches the surface of some plot details. Oof, it's mainly just Kai and Cole fucking around tbh. I love them sm don't come for me.**

 **Anyways, enjoy~**

* * *

"Right then." Kai pursed his lips into a stern, yet assuring smile as he locked eyes with the blond opposite him. "Lloyd, I want to hear what happened on the night of your parents'… passing."

Lloyd swallowed thickly, casting a worried glance to his right, where his Uncle sat. Due to Lloyd being a child, he had to have a guardian with him. He blinked, eyes glossing over as his lip trembled slightly. "I found them dead…"

The brunet was slightly taken aback by the bluntness of the child's voice, but continued anyways. "I know that's it's hard, but you need to tell me everything you know. It can help us find out who did this to them–"

"He's just a child." Wu, the Uncle, spoke up almost bitterly. "You shouldn't be asking him to talk about the murder of his parents–"

"It's my job. Don't you want to know who's responsible?" The elderly man quietened, and Kai focused back on Lloyd. "Just say what you want to, anything will help."

The boy inhaled and exhaled, nodding slowly. "O-Okay…"

* * *

"How was he, then?" Cole muttered, sipping at his coffee. His eyes followed the brunet as he dragged his feet into the office, groaning.

"He basically just went on about shit we already know. Not to mention his Uncle wasn't too pleased with the questions…" He slumped in his chair and ran a hand down his face. "If anything we need to talk to Wu on his own. The guy seems suspicious."

"Are you suggesting he murdered them?" Cole raised a brow, taking another sip of his drink as his spare hand patted about on his desk blindly until it found his notepad and pen, flipping open the notepad and holding the pen steady in his fingers. Without even looking he began noting things down, a smirk spreading across his lips as Kai watched him, shocked.

"How in the hell are you doing that?"

"Doing what?"

"Drinking coffee and writing at the same time!" He exclaimed, losing his voice not to disturb anyone. "Guys can't multitask…!"

"I've ascended to the next level. I'm God." The raven stated, before putting down his pen and chugging the lasts of his coffee, placing the mug down on its coaster.

Kai glared at him playfully. "Damn you and your childhood private tutoring."

"Blame my dad." He uttered. "I used to prefer the term 'child abuse'."

The brunet snickered. "Oh no. Is Cole having flashbacks to his angsty teenage years?"

Cole paused for a moment, swiveling back to his desk and staring down at the notepad. "…Maybe."

Kai grinned. "Aw, chin up, Cole! Everyone has an grunge phase. Heck, even I did–"

"Listening to Panic At The Dicso doesn't make you grunge, Kai." He retorted. "Neither does wearimg edgy wristbands. You were a follower – a sheep, if you will."

"I was, and still am, a trendsetter."

Cole scoffed. "Oh yeah? And what trends have you set?"

Kai scratched the back of his neck, laughing hastily. "Well, you see–"

"Don't lie to me, Kai. You're a shit liar." The raven smiled sweetly, sarcasm dripping from his words like venom. "The only thing you've set is the biggest collection of hair gel."

The taller male gasp, clutching his chest overdramatically. "How _dare_ you!" He growled. "Do _not_ bring the babe magnet into this–"

"For fucks sake…" Cole groaned. "Stop calling it that…"

"–My hair gets me all the hoes, Cole." He stated with a firm nod.

"Oh yeah, cuz there's _sooo_ many hoes around you, isn't there?" His arms folded over his chest. "From the looks of it, I'm your only friend, Kai. Now unless you've got some weird incest thing going on with Nya, your only 'hoe' is apparently me. Because I'm the only person that you hang out with."

Kai huffed. "Let me enjoy my fake popularity. You're more of an entourage, anyways~"

"Wow. I feel _so_ loved."

"Good." He beamed teasingly as Cole rolled his eyes, before the shorter male stood up and grabbed his mug.

"I'm getting a refill. You want anything?" He muttered, jabbing his head in the direction of the coffee machine.

The brunet handed him his own mug, before snapping his fingers repeatedly and kicked his legs up on the desk, crossing them. "Go make me a coffee, Slave!" He called as Cole walked off, not caring that he was sent the middle finger.


End file.
